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1. Sup=Ss

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001

10.0 points

Two men decide to use their cars to pull a

truck stuck in mud. They attach ropes and

one pulls with a force of 813 N at an angle

of 29° with respect to the direction in which

the truck is headed, while the other car pulls

with a force of 1113 N at an angle of 21° with

respect to the same direction.

813 N

121°

1113 N

What is the net forward force exerted on

the truck in the direction it is headed?

Answer in units of N.

29⁰°

002 10.0 points

Consider a man standing on a scale which

is placed in an elevator. When the elevator is

stationary, the scale reading is S..

Scale

Find Sup the scale reading when the el-

evator is moving upward with acceleration

1

a=93, in terms of S..

2. Sup

3. Sup

5. Sup

=

4. Sup =

=

8. Sup

=

7. Sup =

=

10 | 2009 | 10

ا

=

+D

6. Sup=Ss

9176

Ss

7

c

Ss

9. Sup

10. Sup = 0 m/s²

003 (part 1 of 3) 10.0 points

A dragster and driver together have mass

942.2 kg. The dragster, starting from rest,

attains a speed of 25.5 m/s in 0.56 s.

Find the average acceleration of the drag-

ster during this time interval.

Answer in units of m/s².

004 (part 2 of 3) 10.0 points

What is the size of the average force on the

dragster during this time interval?

Answer in units of N.

005 (part 3 of 3) 10.0 points

Assume the driver has a mass of 71.5 kg.

What horizontal force does the seat exert

on the driver?

Answer in units of N.

006 10.0 points

Robert de Niro pushes down the length of the

handle of a 13.8 kg lawn spreader. The handle

makes an angle of 43.1° with the horizontal.

Robert wishes to accelerate the spreader from

rest to 1.38 m/s in 1.5 s.

What force must Robert apply to the han-

dle?/nbrooks (kh46587) - HW 6- Newton's Laws of Motion - hybee - (24141)

013 10.0 points

The distance between two telephone poles is

51 m. When a 1.3 kg bird lands on the

telephone wire midway between the poles, the

wire sags 0.188 m.

The acceleration of gravity is 9.8 m/s².

How much tension in the wire does the bird

produce? Ignore the weight of the wire.

Answer in units of N.

Answer in units of N.

007 10.0 points

Two forces are the only forces acting on a

2.1 kg object which moves with an accelera-

tion of 3.3 m/s² in the positive y direction.

One of the forces acts in the positive z direc-

tion and has a magnitude of 9.9 N.

What is the magnitude of the other force

$₂?

Answer in units of N.

008 10.0 points

A(n) 1330.7 kg car is coasting along a level

road at 37.3 m/s. A constant braking force

is applied, such that the car is stopped in a

distance of 73.3 m.

What is the magnitude of the braking force?

Answer in units of N.

009 (part 1 of 4) 10.0 points

The instruments attached to a weather bal-

loon have a mass of 5.9 kg. The balloon is

released and exerts an upward force of 110 N

on the instruments.

The acceleration of gravity is 9.8 m/s².

What is the acceleration of the balloon and

the instruments?

Answer in units of m/s².

010 (part 2 of 4) 10.0 points

After the balloon has accelerated for 8.2 s, the

instruments are released.

What is the velocity of the instruments at

the moment of their release?

Answer in units of m/s.

011 (part 3 of 4) 10.0 points

Assume: The upward direction is positive.

What net force acts on the instruments

after their release?

Answer in units of N.

012 (part 4 of 4) 10.0 points

How long after their release does the direc-

tion of their velocity first become downward

(negative)?

Answer in units of s.

014 (part 1 of 2) 10.0 points

The knot at the junction is in equilibrium

under the influence of four forces acting on

it. The F force acts from above on the left at

an angle of a with the horizontal. The 5.3 N

force acts from above on the right at an angle

of 46° with the horizontal. The 5.3 N force

acts from below on the right at an angle of

40° with the horizontal. The 5.7 N force acts

from below on the left at an angle of 50° with

the horizontal.

46°

40°

5.3 N

5.3 N

(knot)

5.7 N

50°

Note: F, a are not to scale.

What is the magnitude of the force F?

Answer in units of N.

015 (part 2 of 2) 10.0 points

What is the angle a of the force F as shown

in the figure above?

Answer in units of º.

Fig: 1

Fig: 2